https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98633
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- Hmm. I see in libcody/Makefile.in revision.stamp: $(addprefix $(srcdir)/,. $(SUBDIRS)) @revision=$$(git -C $(srcdir) rev-parse HEAD 2>/dev/null) ;\ if test -n "$$revision" ;\ then revision=git-$$revision ;\ if git -C $(srcdir) status --porcelain 2>/dev/null | grep -vq '^ ' ;\ then revision+=M ;\ fi ;\ else revision=unknown ;\ fi ;\ echo $$revision > $@ and when this happened to me I was committing sth to the tree (uncommitted changes) during the bootstrap. Not sure if the git rev somehow ends up in fatal.o